An Explosive Ordnance Disposal (EOD) team carried out a controlled explosion.
The device had been discovered on a stretch of sand near Collieston.
Police have now left the scene.
Inspector Steven McDonald, of Banff Police Station, said: “Around 10.55am on Tuesday, 19 May, 2020, police were called to a report of unexploded ordnance found on the beach near Collieston.
“The area has been cordoned off as a precaution. EOD attended and carried out a controlled explosion.”
More to follow.